"That was the aim of the whole program - to try and give the coral a chance to grow and we've seen that, despite some of the extreme weather events that we've had."

Other measures under the Government's Reef 2050 Plan will see improvements to the quality of water entering the reef, which will limit the ability of larval-stage starfish to thrive on water-borne algae that results from nutrient-rich waters.

The Government has also funded a second control vessel, Venus 2, as part of the program.

But Mr Moon says more resources may be needed.

"I don’t think we’ve seen the peak of this current outbreak yet," he said.

"I think we’re going to be looking further down the track somewhere around this time next year, given that we’ve already had a spawning season in recent months.

"What we’re going to see - is two boats going to be enough? Possibly, but probably not."

Jairo Rivera from James Cook University helped to develop the single injection and says it is working with scientists from the Sunshine Coast University on a contraceptive to further control the spread of crown-of-thorns starfish.

"We found a protein on the surface of the sperm and that can be [bound] to a molecule that turns the eggs sterile," he said.

"If we can do that, that will be awesome because one single starfish can produce up to 60 million eggs per year."

Mr Rivera says the new method could be ready to trial in two years but $300,000 is needed to support the research.